Description:

The annotator callback is only called on items added to email-type mailboxes.


Config changes:

None.


Upgrade instructions:

In general, no action is required.  In the very unlikely instance that your
installation was relying on an annotator callout processing non-email appends
(like Sieve, events, or contacts), you will need to find another solution.  The
core team does not believe such a configuration is likely to exist.


GitHub issue:

None.
